Question

我使用一段非常简单的代码来更新NSManagedObject，但是保存不会进入持久性存储（SQLite）。没有错误消息，日志看起来还不错，所以我有点迷失。

我已尽可能缩小代码以尝试隔离问题，如下所示。

日志告诉我orderNumber和status设置正确，并且数组的调试输出都是正确的，但我的简单更新仍然失败，没有任何错误。

+ (int) synchOrderWithStatusUpdate:(NSString *)orderNumber : (int)status {
    if ([NWTillHelper isDebug] == 1) {
        NSNumber *statusCheck = [NSNumber numberWithInt:status];
        NSLog(@"WebServices:synchOrderWithStatusUpdate:ordernumber = %@, status = %d, status2 = %@", orderNumber, status, statusCheck);
    }

    synchOrderErrorCode = 0;

    AppDelegate *appDelegate = (AppDelegate *)[[UIApplication sharedApplication]delegate];

    NSManagedObjectContext *context = appDelegate.persistentContainer.viewContext;

    // *** The query for all tables uses orderNumber as selection so we set that up first for re use
    NSPredicate *predicateOrderNumber =[NSPredicate predicateWithFormat:@"orderNumber like[cd] %@", [NWTillHelper getCurrentOrderNumber]];

    NSFetchRequest *fetchRequestOh = [[NSFetchRequest alloc] initWithEntityName:@"OrderHead"];
    NSFetchRequest *fetchRequestOrp = [[NSFetchRequest alloc] initWithEntityName:@"OrderRow"];
    NSFetchRequest *fetchRequestTender = [[NSFetchRequest alloc] initWithEntityName:@"Tender"];

    fetchRequestOh.predicate = predicateOrderNumber;
    fetchRequestOrp.predicate = predicateOrderNumber;
    fetchRequestTender.predicate = predicateOrderNumber;

    fetchRequestOh.resultType = NSDictionaryResultType;
    fetchRequestOrp.resultType = NSDictionaryResultType;
    fetchRequestTender.resultType = NSDictionaryResultType;

    NSError *errorOh = nil;
    NSMutableArray *orderHeads = [[context executeFetchRequest:fetchRequestOh error:&errorOh] mutableCopy];

    NSError *errorOrp = nil;
    NSArray *orderRows = [[context executeFetchRequest:fetchRequestOrp error:&errorOrp] mutableCopy];

    NSError *errorTender = nil;
    NSArray *tenderRows = [[context executeFetchRequest:fetchRequestTender error:&errorTender] mutableCopy];

    if ([NWTillHelper isDebug] == 1) {
        NSLog(@"WebServices:synchOrderWithStatusUpdate:orderHeadsArray: %@", [orderHeads objectAtIndex:0]);
        NSLog(@"WebServices:synchOrderWithStatusUpdate:orderRowsArray: %@", orderRows);
        NSLog(@"WebServices:synchOrderWithStatusUpdate:tenderRowsArray: %@", tenderRows);
    }

    // *** Set the status before upload since this dictates what will happen in backend
    // *** regardless if synch is successful or not
    NSManagedObject *orderHeadObject = nil;
    orderHeadObject = [orderHeads objectAtIndex:0];
    [orderHeadObject setValue:[NSNumber numberWithInt:status] forKey:@"status"];

    // Save the objects to persistent store
    NSError *error = Nil;
    [context save:&error];

    NSLog(@"Jongel Error = %@", error);

    if(error !=nil) {
        if([NWTillHelper isDebug] == 1) {
            NSLog(@"Can't Save! %@ %@", error, [error localizedDescription]);
        }
        synchOrderErrorCode = 99;
    }

    return 10101;

Answer 1

orderHeads被提取为词典。 NSManagedObjectContext将不会知道对字典所做的任何更改。只有NSManagedObjects将由NSManagedObjectContext管理，因此名称为： - ）

尝试将orderHeadObject作为NSManagedObject获取，因为这样可以将更改保存回商店。如果您需要JSON序列化的字典：在进行更改后再次将其作为字典获取。第二次获取将非常快，因为对象的所有值都已缓存，因此CoreData不必从数据库重新加载。

核心数据更新无法保存，也不会出现任何错误，为什么？

1 个答案: